Load cell data sheets often list “seal type” or a similar term. What does this mean for load cell applications? What does this mean for buyers? Should I design my load cell around this functionality?
There are three types of load cell sealing technologies: environmental sealing, hermetic sealing and welding sealing. Each technology offers different levels of airtight and watertight protection. This protection is critical to its acceptable performance. Sealing technology protects internal measurement components from damage.
Environmental sealing techniques use rubber boots, glue on the cover plate, or potting the gauge cavity. Environmental sealing protects the load cell from damage caused by dust and debris. This technology offers moderate protection against humidity. Environmental sealing does not protect the load cell from water immersion or pressure washing.
Sealing technology seals instrument bags with welded caps or sleeves. The cable entry area uses a welded barrier to prevent moisture from “wicking” into the load cell. This technique is most common in stainless steel load cells for heavy washdown or chemical applications. A sealed load cell is a more expensive type of load cell, but it has a longer life in corrosive environments. Hermetically sealed load cells are the most cost-effective solution.
Weld-sealed load cells are the same as sealed load cells, except at the load cell cable exit. Weld-sealed load cells typically have the same load cell cable accessories as environmentally sealed load cells. The instrumentation area is protected by a weld seal; however, the cable entry is not. Sometimes solder seals have conduit adapters for the cables that provide additional protection. Weld-sealed load cells are suitable for environments where the load cell can sometimes get wet. They are not ideal for heavy washdown applications.
Post time: Jun-25-2023
